Contacts

Four gut bacteria decrease risk of asthma

September 30, 2015

Researchers at the Faculty of Medicine and BC Children’s Hospital have found a strategy to prevent asthma: Acquiring four types of gut bacteria within the first three months of life.

The researchers analyzed fecal samples from 319 children and found lower levels of four specific gut bacteria in three-month-old infants who were at an increased risk for asthma. Most babies naturally acquire these four bacteria, nicknamed FLVR (Faecalibacterium, Lachnospira, Veillonella, Rothia), from their environments, but some do not, either because of the circumstances of their birth or other factors.

There were fewer differences in FLVR levels among one-year-old children, meaning the first three months are a critical time period for a baby’s developing immune system. The researchers confirmed these findings in mice and also discovered that newborn mice inoculated with the FLVR bacteria developed less severe asthma. The research was published today in Science Translational Medicine.

“This research supports the hygiene hypothesis that we’re making our environment too clean. It shows that gut bacteria play a role in asthma, but it is early in life when the baby’s immune system is being established,” said the study’s co-lead researcher B. Brett Finlay, Peter Wall Distinguished Professor in the Department of Biochemistry and Molecular Biology, the Department of Microbiology and Immunology, and the Michael Smith Laboratories.

More vaginal deliveries and breast-feeding and less use of antibiotics could help nurture the microbes needed to avoid asthma and other diseases, Dr. Finlay says.

Asthma rates have increased dramatically since the 1950s and now affect up to 20 per cent of children in western countries. The discovery opens the door to developing probiotic treatments for infants that prevent asthma. The finding could also be used to develop a test for predicting which children are at risk of developing asthma.

“This discovery gives us new potential ways to prevent this disease that is life-threatening for many children. It shows there’s a short, maybe 100-day window for giving babies therapeutic interventions to protect against asthma,” said co-lead researcher Stuart Turvey, the Aubrey J. Tingle Professor of Pediatric Immunology, a pediatric immunologist at BC Children’s Hospital, and Director of Clinical Research at the Child & Family Research Institute.

More than 300 families from across Canada participated in this research through the Canadian Healthy Infant Longitudinal Development (CHILD) Study. The researchers say that further study with a larger number of children is required to confirm these findings and reveal how these bacteria influence the development of asthma.